Severe Local Storm: how HazardNet classifies and scores it
Squall wind plus a convective downpour.
How the model arrives at this class
Classified from the same drivers; Severe Local Storm and Tropical Cyclone compete directly on the wind term and are separated by the rainfall pattern and the other drivers.
Uncalibrated softmax, as above.
Advisory levels follow the published alert policy and the escalation boundaries of the responsible authorities; nothing here overrides them.
The independent physics cross-check
Uses the peak 24-hour rainfall rather than the horizon total, precisely so a wet fortnight is not read as a squall line: the defect the corrected wiring removed.
Drivers: maximum wind in the horizon (W, km/h) · wettest 24 hours in that horizon (P_peak, mm).
- Expression: 0.6*clip((W-50)/100) + 0.4*clip(P_peak/100)
- That expression is executed against the pipeline’s own implementation by the content tests in CI: this page cannot silently describe a formula the pipeline no longer runs.
What the current run says about Severe Local Storm
The run this deployment ships (prediction date 2026-11-02) classifies no district trajectory as Severe Local Storm across Days 1 to 15. An absence of severe local storm in one run is not a statement that the hazard cannot occur this season.
Season and geography
Typical season: March–May (Nor'wester / Kalbaishakhi), plus pre-monsoon squall lines. This describes when the hazard is climatologically plausible, not when this run flags it.
What this class cannot tell you
- No convective-available-potential-energy, no storm-top height, no hail: the meteorology that defines a Nor'wester is not an input.
- Peak wind in a district aggregate understates the local maximum that damages a bazaar.
- Hail and lightning, the two things that actually kill in a Kalbaishakhi, are not represented at all.
- Confidence is published as an uncalibrated model score; no calibration accuracy is claimed.
Inputs behind it
Published assessments and official bulletins are the record; this site reports what they name.
- published forecast records
Questions and answers
Is a high Severe Local Storm severity a prediction of damage?
No. The severity index is the model's continuous score for how strongly the drivers resemble this class, on a 0.00–1.00 scale. It is not a probability, not a percentage, and it does not model exposure. The physics cross-check is a second, independent estimate; where the two diverge, both numbers are shown rather than averaged.
Why is the confidence not a probability of Severe Local Storm?
The published confidence is the model's own confidence over its eight classes, labelled uncalibrated_model_confidence in the data. It says how certain the classifier is about the class it picked, not how often that class actually materialises. No calibration has been fitted yet, which is also why nothing above the WATCH level can be published automatically.
Which districts does this page cover?
The district pages cover all 64 districts. This page summarises the districts the current run covers: a run can be partial, and the coverage stamp on the snapshot says exactly how partial, which the status page reports.
HazardNet is not an official warning service. Official warnings come from BMD and FFWC. In an emergency call 999.
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